patch-2.4.20 linux-2.4.20/include/asm-x86_64/i387.h

• Lines: 152
• Date: Thu Nov 28 15:53:15 2002
• Orig file: linux-2.4.19/include/asm-x86_64/i387.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/include/asm-x86_64/i387.h linux-2.4.20/include/asm-x86_64/i387.h
@@ -0,0 +1,151 @@
+/*
+ * include/asm-x86_64/i387.h
+ *
+ * Copyright (C) 1994 Linus Torvalds
+ *
+ * Pentium III FXSR, SSE support
+ * General FPU state handling cleanups
+ *	Gareth Hughes <gareth@valinux.com>, May 2000
+ * x86-64 work by Andi Kleen 2002
+ */
+
+#ifndef __ASM_X86_64_I387_H
+#define __ASM_X86_64_I387_H
+
+#include <linux/sched.h>
+#include <asm/processor.h>
+#include <asm/sigcontext.h>
+#include <asm/user.h>
+
+extern void init_fpu(void);
+int save_i387( struct _fpstate *buf);
+
+/*
+ * FPU lazy state save handling...
+ */
+
+#define kernel_fpu_end() stts()
+
+#define unlazy_fpu( tsk ) do { \
+	if ( tsk->flags & PF_USEDFPU ) \
+		save_init_fpu( tsk ); \
+} while (0)
+
+#define clear_fpu( tsk ) do { \
+	if ( tsk->flags & PF_USEDFPU ) { \
+		asm volatile("fwait"); \
+		tsk->flags &= ~PF_USEDFPU; \
+		stts(); \
+	} \
+} while (0)
+
+#define load_mxcsr( val ) do { \
+		unsigned long __mxcsr = ((unsigned long)(val) & 0xffbf); \
+		asm volatile( "ldmxcsr %0" : : "m" (__mxcsr) ); \
+} while (0)
+
+/*
+ * ptrace request handers...
+ */
+extern int get_fpregs( struct user_i387_struct *buf,
+		       struct task_struct *tsk );
+extern int set_fpregs( struct task_struct *tsk,
+		       struct user_i387_struct *buf );
+
+/*
+ * FPU state for core dumps...
+ */
+extern int dump_fpu( struct pt_regs *regs,
+		     struct user_i387_struct *fpu );
+
+/* 
+ * i387 state interaction
+ */
+#define get_fpu_mxcsr(t) ((t)->thread.i387.fxsave.mxcsr)
+#define get_fpu_cwd(t) ((t)->thread.i387.fxsave.cwd)
+#define get_fpu_fxsr_twd(t) ((t)->thread.i387.fxsave.twd)
+#define get_fpu_swd(t) ((t)->thread.i387.fxsave.swd)
+#define set_fpu_cwd(t,val) ((t)->thread.i387.fxsave.cwd = (val))
+#define set_fpu_swd(t,val) ((t)->thread.i387.fxsave.swd = (val))
+#define set_fpu_fxsr_twd(t,val) ((t)->thread.i387.fxsave.twd = (val))
+#define set_fpu_mxcsr(t,val) ((t)->thread.i387.fxsave.mxcsr = (val)&0xffbf)
+
+static inline int restore_fpu_checking(struct i387_fxsave_struct *fx) 
+{ 
+	int err;
+	asm volatile("1:  rex64 ; fxrstor (%[fx])\n\t"
+		     "2:\n"
+		     ".section .fixup,\"ax\"\n"
+		     "3:  movl $-1,%[err]\n"
+		     "    jmp  2b\n"
+		     ".previous\n"
+		     ".section __ex_table,\"a\"\n"
+		     "   .align 8\n"
+		     "   .quad  1b,3b\n"
+		     ".previous"
+		     : [err] "=r" (err)
+		     : [fx] "r" (fx), "0" (0)); 
+	return err;
+} 
+
+static inline int save_i387_checking(struct i387_fxsave_struct *fx) 
+{ 
+	int err;
+	asm volatile("1:  rex64 ; fxsave (%[fx])\n\t"
+		     "2:\n"
+		     ".section .fixup,\"ax\"\n"
+		     "3:  movl $-1,%[err]\n"
+		     "    jmp  2b\n"
+		     ".previous\n"
+		     ".section __ex_table,\"a\"\n"
+		     "   .align 8\n"
+		     "   .quad  1b,3b\n"
+		     ".previous"
+		     : [err] "=r" (err)
+		     : [fx] "r" (fx), "0" (0)); 
+	return err;
+} 
+
+static inline void kernel_fpu_begin(void)
+{
+	struct task_struct *tsk = current;
+	if (tsk->flags & PF_USEDFPU) {
+		asm volatile("fxsave %0 ; fnclex"
+			      : "=m" (tsk->thread.i387.fxsave));
+		tsk->flags &= ~PF_USEDFPU;
+		return;
+	}
+	clts();
+}
+
+static inline void save_init_fpu( struct task_struct *tsk )
+{
+	asm volatile( "fxsave %0 ; fnclex"
+		      : "=m" (tsk->thread.i387.fxsave));
+	tsk->flags &= ~PF_USEDFPU;
+	stts();
+}
+
+/* 
+ * This restores directly out of user space. Exceptions are handled.
+ */ 
+static inline int restore_i387(struct _fpstate *buf)
+{
+	return restore_fpu_checking((struct i387_fxsave_struct *)buf);
+}
+
+
+static inline void empty_fpu(struct task_struct *child)
+{
+	if (!child->used_math) {
+		/* Simulate an empty FPU. */
+		memset(&child->thread.i387.fxsave,0,sizeof(struct i387_fxsave_struct));
+		child->thread.i387.fxsave.cwd = 0x037f; 
+		child->thread.i387.fxsave.swd = 0;
+		child->thread.i387.fxsave.twd = 0; 
+		child->thread.i387.fxsave.mxcsr = 0x1f80;
+	}
+	child->used_math = 1; 
+}		
+
+#endif /* __ASM_X86_64_I387_H */